Receiving an 18 on her latest test causes Ayumi grief as she realizes everyone else got at least an 80 on theirs. She is relentlessly teased by two male classmates when Megu -Ayumi's friend- shows up to tell them off. Megu ignores the chatter of bewildered students surrounding her, surprised someone as smart as her would even be in the E classroom speaking to Ayumi of all people. She's a student of Special Class A. With that, Megu asks Ayumi how she did. Unwilling to confess, she claims she passed as her mood slowly worsens, hearing nearby girls wonder why Megu would be friends with someone like her.
Ayumi's day worsens when she greets her irate mother, who asks why she didn't study before her test. She remarks upon the embarrassment Ayumi causes her, leaving her husband to try calming her as Ayumi retreats to her bedroom. There she weeps as she remembers first meeting Megu back when they took started cram school. A teacher scolded them for speaking during an exam. They laughed about it behind his back and since then have been good friends. Unfortunately, Megu's grades continued rising and now she's extremely far away. She can't help but feel envious of Megu for coming from such a gifted family.
Forced to study, Ayumi grumpily cleans the mess of magazines off of her bed when she happens to see an ad for a Brain Supplement. She initially writes it of as a joke- but finding out that they give free samples, she is suddenly enticed and decides to try it out.
After a week, the package arrives and Ayumi opens it in her bedroom to find a sheet warning her to only take one pill per day, and she is asked to write down the date of when she started- in order to supply her properly. She also finds a review sheet from a few people who have tried the pill, and seeing the good opinions, she has high hopes. She quickly downs one and takes off for cram school, where she is shown initially struggling against an Arithmetic paper. She has no idea what to do and the pill's done nothing yet. But once she reads the equation, she is startled when the answer suddenly appears in her mind. In no time she manages to fill out the entire sheet.
Receiving a 90 on it, she -along with her classmates and Teacher- are very surprised. When she meets up with Megu, she is shocked to hear that even Class A is talking about it. Megu couldn't be happier, explaining how she had started worrying over Ayumi due to knowing how difficult it's been for her. Ayumi is touched by Megu's concern and she heads home, where her parents prepared a celebratory dinner for her.
Seeing how successful one supplement was, Ayumi continues to take them and improve and she grows more confident in herself- sure she might even be able to get into a top ranking school at this rate. Her grades improve so well that she even joins Megu's Special A Class; but oddly, she is ignored when she tries to get Megu's attention. Once class ends, Megu approaches Ayumi and asks if she wants to join her and a few girls as they wait to speak to the Teacher. Ayumi refuses in order to get straight home to catch a show she likes, and she takes off while remarking upon how strange it is for Megu to not understand something.
Suddenly, she realizes that she's forgotten her pencil case and rushes back to retrieve it. But seeing the girls still in the room she patiently waits to avoid rudely interrupting. Although, she isn't able to ignore her growing curiosity upon hearing her name come up. She is shocked as the girls go on to point out the strangeness of the stupidest kid in Class E suddenly improving with no effort. Not only that but she never shows her work, so she has to be cheating. As they speak Ayumi thinks and wonders if taking the supplements actually count as cheating; she honestly doesn't think so though, because it pulls out potential from within her mind. She desperately pleads Megu to defend her, but is driven to tears after she agrees and points out the suspicions of the Teachers as well- but they don't have any proof to actually bring it up.
Driven to tears, Ayumi silently cries and questions Megu's friendship while opening a bottle of supplements. She pours several out and takes them.
As a result of her rash decision, Ayumi is shown to be improving even further- to the point of doing high school-level work as she perfects everything and even includes bonus work for more points. Guided by the pain Megu left her feeling, Ayumi gleefully rubs this in her face by pointing out that she is chosen and how she never has to study; or cheat, words that leave Megu shaken as other students begin chattering.
While happily making her way home Ayumi mockingly recalls Megu's expression and thinks about the many famous schools she was given pamphlets for by the Teacher. She isn't sure which one she'd like to apply to, but before heading into her home she finds a strange letter in her mailbox from the supplement firm. She opens it to see that she has been chosen and is startled as they point out she broke the one pill a day rule. Now that she is a graduate, she is at fault and has to be collected for studying. Alarmed, Ayumi runs inside and locks the door, wondering how the firm can just take her away. It's then she recalls the review sheet that featured other graduates and realizes that they must have overdosed like she did.
It's then her phone begins to ring. Ayumi ignores it fearing the worst- but as she hears Megu's voice she hesitantly listens to the message she leaves. In tears, Megu apologizes for allowing Ayumi to overhear the discussion she had a few days ago with those other girls. She explains how she only said it out of anger due to how little effort Ayumi puts into her grades, yet she spends every single day studying late into the night with her mother. She never realized before now that Ayumi must have been trying her best and nobody has ever noticed. She hopes Ayumi realizes that she never meant to hurt her, and she has come to the conclusion that she must really be a chosen.
Ayumi sadly listens as Megu's message comes to an end; and she can only sadly stand there in defeat as her doorbell starts ringing...
Some time passes and a woman sits in a cafe with her friend. She is tired of her lazy son and the little effort he puts into his grades. It's then she comes across the supplement ad and finds a page dedicated to reviews; including a brand new one with Ayumi.
- Downer Ending: After Ayumi finds out the supplement firm will be collecting her for study, she gets a call from the apologetic Megu who explains how she had been feeling. As Ayumi remorsefully realizes her mistake, the door begins to ring...
- Education Mama: Both Ayumi and Megu have mothers like this. Ayumi's mother is very strict when Ayumi does poorly in school, while Megu's mother is a Teacher and spends several hours a day studying with her.
- Karmic Twist Ending
- Super Intelligence: In the form of a pill that increase a person's latent intelligence. But they are warned to only take one pill a day.